International reference methods for the determination of cigarette smoke yields have been fully defined after the publication of the latest revised ISO methods, in 1991. Validated data may be achieved in order both to verify the compliance of the produced cigarettes with the prearranged standards of production, and to control the tar and nicotine yields declared on the labels. Aiming at the proper implementation of the ISO methods, Amministrazione dei Monopoli di Stato had to solve problems quite different from those of any other cigarette manufacturer, because of the high number of its production sites (twenty factories located all over the country). In addition, the complexity of providing each factory laboratory with new updated equipments at the same time, should not be neglected. The paper reports on the attempt to set a single criterion for the evaluation of the analytical results, which enables to guarantee Quality Assurance of the smoking procedures in the different laboratories. Monitoring of the smoke analysis data was performed, in three stages. Practical 'evaluation tests' were developed, which allow to compare the analytical procedures of each laboratory and, by interpreting the experimental results, to make sure that validated data are achieved when verifying the smoke cigarette yields.